Créditos: Comité científico CovidLeer más
An mRNA vaccine for ticks
Repeated exposures to the black-legged tick, Ixodes scapularis, can lead to acquired resistance against ticks or “tick immunity.” To bypass the need for repeated exposures while still generating tick resistance, Sajid et al. developed an mRNA vaccine that encoded for 19 I. scapularis salivary proteins (19ISP). Guinea pigs vaccinated with 19ISP developed erythema at the site of tick attachment, a feature of acquired tick resistance. This led to poor tick feeding and, in the case of ticks infected with the Lyme disease agent, Borrelia burgdorferi, reduced transmission of the pathogen. Thus, 19ISP is a promising candidate for antitick vaccines that may also prevent transmission of tick-borne diseases.
Ixodes scapularis ticks transmit many pathogens that cause human disease, including Borrelia burgdorferi. Acquired resistance to I. scapularis due to repeated tick exposure has the potential to prevent tick-borne infectious diseases, and salivary proteins have been postulated to contribute to this process. We examined the ability of lipid nanoparticle–containing nucleoside-modified mRNAs encoding 19 I. scapularis salivary proteins (19ISP) to enhance the recognition of a tick bite and diminish I. scapularis engorgement on a host and thereby prevent B. burgdorferi infection. Guinea pigs were immunized with a 19ISP mRNA vaccine and subsequently challenged with I. scapularis. Animals administered 19ISP developed erythema at the bite site shortly after ticks began to attach, and these ticks fed poorly, marked by early detachment and decreased engorgement weights. 19ISP immunization also impeded B. burgdorferi transmission in the guinea pigs. The effective induction of local redness early after I. scapularis attachment and the inability of the ticks to take a normal blood meal suggest that 19ISP may be used either alone or in conjunction with traditional pathogen-based vaccines for the prevention of Lyme disease, and potentially other tick-borne infections.
Créditos: Comité científico Covid